RGMII RX

For the RGMII interface, the Double Data I/O (DDIO) option must be enabled for the receive data and control signals. Table 1 and Table 2 show the recommended Block Editor settings for rgmii_rxd and rgmii_rx_ctl.

Table 1. Block Editor Settings for rgmii_rxd, and rgmii_rx_ctl Targeting Trion DevicesWith First Sampling of RGMII Receive Data Option Set to Rising Edge
Parameter Setting
rgmii_rxd [3:0] rgmii_rx_ctl
Mode Input Input
Register Option Register Register
Double Data I/O Option Resync Resync
Clock Pin Name rgmii_rxc rgmii_rxc
Pin Name (HI) rgmii_rxd_HI rgmii_rx_ctl_HI
Pin Name (LO) rgmii_rxd_LO rgmii_rx_ctl_LO
Note: Due to the limited availability of GPIO pins with capability on the Trion T120 BGA324 development board, the example design with external PHY targeting this device cannot assign the RGMII control signals (rgmii_tx_ctl and rgmii_rx_ctl) to a standard DDIO block.
To accommodate for this specific hardware limitation, the following workaround is implemented in tsemac_ex.v:
assign rgmii_tx_ctl = rgmii_tx_ctl_HI | rgmii_tx_ctl_LO; 
assign rgmii_rx_ctl_HI = rgmii_rx_ctl;
assign rgmii_rx_ctl_LO = rgmii_rx_ctl;
Table 2. Block Editor Settings for rgmii_rxd, and rgmii_rx_ctl Targeting Titanium/ Topaz DevicesWith First Sampling of RGMII Receive Data Option Set to Falling Edge
Parameter Setting
rgmii_rxd [3:0] rgmii_rx_ctl
Mode Input Input
Register Option Register Register
Double Data I/O Option Pipeline Pipeline
Clock Pin Name rgmii_rxc rgmii_rxc
Pin Name (HI) rgmii_rxd_LO rgmii_rx_ctl_LO
Pin Name (LO) rgmii_rxd_HI rgmii_rx_ctl_HI

In the Efinity Interface Designer, use the Create Block/ Create Bus menu to add these signals and configure them according to Table 1 and Table 2.

Figure 1 and Figure 2 illustrate the conversion from RGMII RX to RX AXI ST at 1000 Mbps with the recommended block editor settings in Table 1 and Table 2.

Figure 1. Conversion from RGMII RX to RX AXI ST at 1000 Mbps (Trion Block Editor Settings). Based on Table 1

Figure 2. Conversion from RGMII RX to RX AXI ST at 1000 Mbps (Titanium/ Topaz Block Editor Settings. Based on Table 2